Braking device for wheel chairs



H. w. FOLEY Filed Feb. 21. 1946 [N V EN TOR.

June 3, 1952 BRAKING DEVICE FOR WHEEbCl-WERS 7 w w I 1,,

Patented June 3, 1952 V. .2 ,599,051 BRAKING DEVICE non WHEEL onAm-sHanceal W. Foley, ToledogvOhio, assignorwo Gendron Wheel Company,Perrysburg, Ohio, a

corporation of Ohio Application February 21, 1946, 'SerialN'o. 649,198

' 1Claim (Cl.-188---80.=)

movement to the wheel shaft increasing or decreasing frictionalresistance to wheel movement.

A further object of this invention is to provide an invalid chair havingIa stub shaft moveable laterally in the axle housing in response to setscrew operation for regulating resistance to chair movement.

Other objects and advantages of this invention will hereinafter appearand for purposes of illustration but not of limitation, an embodiment ofthe invention is shown in the accompanying drawings in which:

Figure 1 is a perspective view of an invalid chair embodying theinvention;

Figure 2 is a fragmentary sectional elevational view through one endportion of the axle assembly showing the invention in detail; and

Figure 3 is a sectional elevation taken on the line 3-3 of Figure 2.

The illustrated embodiment of the invention comprises an invalid chairit! having a seat ll positioned over the rear axle housing l2 byinterassociated metallic braces l3 and supported thereon by coil springs[4 connecting the underside of the seat II to the axle l2 in a manner topermit a degree of springiness which absorbs the shocks to providecomfortable riding qualties. A foot rest l5 stationarily secured to theforward portion of the seat is further supported by a transverse axle l6having the small wheels ll rotatably mounted on the outwardly extendingends. Rigid metallic cross braces I8 interconnects the lower forwardaxle IS with the main axle I2 to comprise a sturdy chair frame.

Mounted on the ends of the axle l2 are a pair of large wheels H! which,ordinarily, are freely rotatable, however, not infrequently, it isdesirable to vary the effort required to impart movement to the invalidchair and for such purposes means are provided for increasing ordecreasing the frictional forces between rotating parts.

For purposes of clarity description will be made of but one end of theaxle section adapted for the adjustments described, it being understoodthat a similar arrangement may be made in connection with the wheelsmounted on the other end of the axle or other axles.

Figure 2 shows an aperture 20 extending axial- .ly in the end portion ofthe axle housing 12 forming a sleevesecti'on 21. An aperture :22 throughthe upper and rearward portion of the sleeve sec-- tion 121 is threadedfor engagement with .areset screw 23 having an inwardly disposed gwedgeshaped nose 24 and an outwardly disposed stub portion 25 which ispartially threaded for positioningza lock bolt 26 which secures the setscrew in the verticallyadju'sted position when. tightened down upon thesleeve surface. Itismanifest that tumung movement :of the .set :screw'28 inoneh-rdimotion or the other .imparts upward or downward vmovementof .said set screw in relation --to the axle housing. p Y

A stub shaft 21, axially moveable in the sleeve section 2|, has acut-out 28 on the upper inner end portion which provides a flattenedshoulder 29 having a vertically disposed aperture 30 therethrough whichis operatively engaged by the wedge end 24 of the set screw 23 in theassembled relation.

The lateral open ends of the wheel mounting hub 3| positioned on the endof the stub shaft extending outwardly from the axle housing 12 isenclosed by metallic outwardly facing cup shaped {members 32a and 32b inwhich anti-friction bearings 33 are positioned to operate; at one hubend between the surfaces of the cup shaped member 32a, the stub shaft21, and the end of the axle housing 2!, and at the other hub and.between the cup shaped member 32b, the stub shaft and the enlarged head34 secured to the end of the stub shaft.

It is a well known concept in physics that the forces required toovercome the frictional resistance between surfaces whether static ordynamic bears a proportional relation to the normal pressure between thebodies. Thus it is apparent that when transitory shifting movement isimparted to the stub shaft 21 causing the head member 34 to bear morefirmly against the anti-friction bearings 33 the forces required toeffect wheel turning movement is increased in proportion to theincreased lateral or normal pressure. It' is also evident that, as thestub shaft is released for outward shifting movement the normalpressures will be relaxed as a result of such movements whichautomatically take place.

Transitory shifting movement is imparted to the stub shaft 21 inresponse to the operation of the set-screw 23 which engages the aperture30. Set-screw turning movements which results in movement of the nose inthe downwardly direction effects the inward displacement of the stubshaft in view of the wedge action between the wedge shaped nose 24 andthe peripheral upper edge of the aperture 30, increasing the resistanceto chair movements as previously explained. Operation of the set screwin the upward direc tion liberates the stub shaft for limited outwardmovement in relief of said normal pressure.

Thus, it is obvious that merely by the operation of the set-screw, thenormal contact pressure on the antifriction means may be varied over awide range for adjusting chair movements. 7 It is also evident that thewheel and stub shaft may be mounted or removed merely by the operationof the set screw in the upwardly direction a distance sufficient toclear the upper surface of the shoulder 29, freeing the stub shaft forlateral sliding movement.

It is evident that I have invented an invalid chair the movements ofwhich maybe readily controlled by the simple operation of a set screwwhich is within the range of the occupant.

.It is to beunderstood that numerous changes in details'of construction,arrangement and operation may be effected without departing from 'thespirit of the invention especially as defined in the appended claim.

' What I claim is:

In an invalid chair, a stationary axle housing having-a tubular endportion, a stub shaft having a part fitting said end portion and axiallyshiftable therein, the free end of said stub shaft extending outside ofsaid tubular end portion, a

supporting wheel, a hub member mounted for ro- 4 tween the hub memberand stub shaft, one ballbearing unit engageable with the outer endportion of said tubular end portion, a head member on the outer end ofsaid stub shaft adapted to bear against the other ball-bearing unit, anaperture in that part of said stub shaft inside the tubular end portion,and a set screw on said tubular end portion having a conical end portionengageable with an edge of the stub aperture whereby upon tightening theset screw, axial shifting movement is imparted to the stub shaft forfrictionally engaging the ball-bearing units and thus exerting a brakingaction on the hub.

' HANCEAL W. FOLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Hofer Oct. 6, 1936 Williamson Mar. 25,1890 Cole Jan. 9, 1894 Case Aug. 1, 1899 Myers Mar. 10,v 1925 GuerberJuly 6, 1926 Showers May 10, 1927 FOREIGN PATENTS Country Date GreatBritain July 11, 1904 Great Britain July 11, 1905 Number Re. 20,126424,398 512,279 630,033 1,528,841 1,59 1,529 1,628,559

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